1. Field of the Invention
The present invention relates to a boarding ramp device for an aircraft wherein a single door is provided that includes a window in its upper part for opening and closing an opening in a body of the aircraft. The door is pivotally supported at its lower part by the body with a foldable boarding ramp being provided on an inner face of the door.
2. Description of Background Art
An aircraft such as a business passenger aircraft having a body of a relatively small diameter includes a boarding ramp on an inner face of a door (face opposed to a passenger compartment) in order to open and close an opening provided in a body for ingress and egress of passengers. U.S. Pat. No. 2,910,255 and U.S. Pat. No. 4,086,726 disclose a boarding ramp provided on an inner face of the door, wherein when the door that is pivotally supported at its lower end by the body is opened outwardly and an upper end of the door nears the ground, the ramp is diagonally positioned so as to connect the opening of the body to the ground.
However, the boarding ramp described in U.S. Pat. No. 2,910,255 and U.S. Pat. No. 4,086,726 projects into the passenger compartment from the inner face of the door in the state when the door is closed, leading to a problem that a space in the passenger compartment is oppressed. Also, the exposed boarding ramp impairs the appearance of the passenger compartment, leading to a possibility that the clothes of the passengers may be smeared with mud or the like adhering to the boarding ramp. Further, a window can not be provided in the door due to an obstruction by the boarding ramp. Thus, a problem results wherein the passengers have an oppressed feeling.
In this situation, Beechcraft SUPER KING AIR of Raytheon Aircraft Company employs a boarding ramp including a door pivotally supported at its lower end by an aircraft body with a plurality of steps swingably supported at their base ends by the inner face of the door. The steps are folded along the inner face of the door when the door is closed and the steps forms the boarding ramp by swinging into a deployed position when the door is opened.
The boarding ramp of SUPER KING AIR can effectively use the space of the passenger compartment since the steps can be folded, but does not yet solve the problems that the boarding ramp impairs the aesthetic appearance of the passenger compartment. In addition, the door does not have a window which leads to an oppressed feeling to the passengers.